If you know places that homeless people already go to where you live, it probably won't be so bad. For some reason, the homeless will leave shit behind like clothes or jackets or whatever and you can nab them. Even if you can't, knowing where they sleep means you'll know more or less where you can sleep before you get fully used to it all as well. If the weather is nice, you might even be able to do shit like find crabapple trees to get food from instead of scrounging around in dumpsters or wandering around downtown at night until you find something and hoping it won't make you sick. Honestly, dumpster diving seems like a good hobby to get into as well if you're afraid of becoming homeless, and if you really want to you can "trial run" being homeless too (especially if you live somewhere where the weather is decently nice) e.g. by sleeping outside for a day to see if you can handle it (you probably won't, but knowing your exact limits might be good). Some places will ship away the homeless to warmer climes if they can spot them, so knowing e.g. the location of shelters and how to access resources (or just the police so they can haul you off to said warmer climes) could be good too if you're looking to prep. Not sure about anything else